Thermoresponsive apparatus



Aug. 16, 1932. D, wool, 1,872,208

'I'HBRIORESPOHSIVE APPARATUS Filed July 1. 1927 II I LL-LJ lllllllllllVIIIIIV'I'I fiver-(hark Patented Aug. 16, 1932 UNITED STATES PATENT.OFFICE JOSEPH D. WOOD, OF WOLLASTON, MASSACHUSETTS, ASSIGNOR 1'0 GON'DITELEG'IBICAL MANUFACTURING CORPORATION, OF SOUTH BOSTON, MASSACHUSETTS, ACORPORA- I'HERMORESPONSIVE APPARATUS Application filed Jul 1, 1927.Serial no. 202,940.

This invention relates to electrically actuated thermo-responsivedevices especially adapted to effect the opening of an electric switchupon overload in the switch circuit, although not necessarily restrictedto such use.

An object of the invention is the provision of a thermo-responsivedevice as a unitary piece of apparatus adapted for many differentpurposes.

A further object is the provision of a thermo-responsive apparatushaving a spring tensioned actuating member with means governed by thethermo-responsive elements to hold said member in set condition and torelease it for movement under the action of its spring to effect thetripping of the switch or the control of some suitable circuit ordevice, combined with means to efiect the manual resetting of theactuating member after it has been operated.

A further object of the invention is a novel form of thermo-responsiveapparatus having a spring tensioned actuating member normal 1y held inset position in readiness for operation and a plurality ofthermo-responsive elements each adapted independently and all conjointlyto eil'ect the release of the actuating element for operation.

A further object is generally to improve the construction and operationof electrically actuated thermo-responsive apparatus.

The device embodying this invention is described in my co-pendingapplication Serial No. 202.950 filed-July l. 1927.

Fig. 1 is a side elevation of the thermoresponsive apparatus embodyingthe invention.

Fig. 2 is an end view of the apparatus of Fig. 1.

Fig. 3 is a perspective view of the tripping frame.

Fig. i is an end view partly in section of one of the theme-responsivedevices.

Fig. 5 is a longitudinal sectional view taken along line 55 of Fig. 4.

tended between the holding frame and the thermo-responsive devices.

Fig. 8 is a section diagram illustrating the manner in which athermo-responsive de-- vice can be connected in an electric circuit.

The thermo-responsive apparatus embodying this invention comprises asupporting frame having the spaced integral upstanding side walls 10 and12 and the bottom connecting wall 14. A tripping frame comprising a pairof closely spaced plates 16 and 18 is pivotally mounted on a bolt 20extended between and carried by the upper portions of the side walls.Said plates 16 and 18 are riveted together at appropriate points and areprovided with flat upper faces 22 which are adapted to strike againstthe latch 24 of a switch 26 to effect the opening of the switch; or toactuate some other appropriate mechanism. A tensile spring 28 isdisposed between said plates 16 and 18 and has its upper end connectedwith a pin 30 of the tripping frame and its lower end connected with apin 32 carried by the side walls 10 and 12 in the lower portion thereof.Said spring is disposed at one side of the pivotal center of thetripping frame and so biases the frame for rotation in acounter-clockwise direction as viewed in Fig. 1. i

The frame is normally held in the set position illustrated in Fig. 1 bya holding frame 36 which has spaced side walls 38 pivoted on the pin 32and upstanding ears 40 between which a roller 42 is journalled. Saidroller is adapted to overlie a roller 44 carried between the plates 16and 18 of the tripping frame to hold the tripping frame in set position.A compression spring 46 is disposed under the holding frame and servesnormally to hold it in the elevated position shown in Fig. I, and inengagement with the tripping frame.

When the tripping frame is released, it is adapted to move upward underthe action of the tensile spring 28 and is'adapted to remain in elevatedposition until reset. The frame is adapted to be reset by a resettingpin 48 which may be manually operated and which works in an arcnate slot50 in the side wall 10 of the supporting frame and is adapted to engage9. depending car 52 of the plate 16 of the tripping frame. thus to moveit in a clockwise direction into re-engagcmcut with the holdin frame.

Figs. 4 and 5. The thermo-responsive desg pisive elements are received.

vices are identical and but one needs to be described. Each device iscarried by a bracket 53 having spaced ears 54 at the end provided withslots 56 in which the tbermo-re- A screw 58 ing an enlarged head 60 isreceived in one of the cars 54 and an insulating bushing, (32 isreceived in the other car. A screw (54 is extended through said bushingcoaxially with o the screw )8 and is held in location by the nut 66. Aheater element comprising a spiral coil 68 of suitable resistancematerial is extended between and is secured electrically to the screws.A cylindrical metal tube 70 surrounds the heating element and isrotatable on the enlarged head 60 of the screw 58 and upon the head ofthe bushing 62. A spiral therino-responsive member 72 of tubular orhelical formation formed of a strip of thermostatic metal composed oftwo metals having dissimila expansion COQfll(i8nlS. as copper and ironfixedly united together, is received within the tube 70 and has one endthereof fixed to the tube by the rivet 74. The other and free end 76 isextended freely through an opening 77 in the side of the tube and has anoutwardly projecting tongue 78. The supporting brackets for thethcrmo-rcsponsive elements are secured one above the other to the sidewall 12 of the supporting frame and the tongues 78 are received invcrtically elongated slots 80 of a vertical connecting member 82. thelower end of which is connected loosely with a pin 84 carried by theholding frame 36.

The heater elements are. adapted to be heated by current from someappropriate source a currentset up in the secondary winding of a currenttransformer 83. 8. which is included in series with the circuit 85 ofthe switch 26. As thus arranged. the spiral thermostatic elements 'i'Lare adapted to expand when sufficiently heated and to more the free ends76 thereof i'lownwarilly. thus moving the holding frame .lfi downwardlyagainst the action of thispring 4i and releasing the tripping frame 16which is thus free to move upwardly and trip the switch open. The timeand current scttiuirs of the thcrino-rcsponsivc element n? lvaried byrotating the tubes Tl") :i ml 2h ing the positions of the free ends ofthe lliii'- niostatic elements in the slots oi the con: ing strip 82.For this purpose plates (1 V A; secured to said tubes at similar endsthe; mi

and are pivotally connected with a vertical adjusting rod 88, the upperend of which extends through an ear of the side Wall 12 of thesupporting bracket and has a screw threaded nut 9:2 thereon. It isapparent that by rotating the nut 92, the rod 88 may be raised andlowered, thus to rotate the tubes 70 about their axes and change theadjustment of the thermo-responsive elements.

Preferably the thermostatic element 72 is arranged close to the innerface of the tube 70 with the material of least expansion outermost.Thus, in Fig. 6, the copper section 720*. of the thermostatic element isinnermost and the iron section 72?) outermost. This arrangement,combined with the heat absorbing and dissipating characteristics of themetal tube 70, provides a device which is sensitive to sudden overloadsso that it can trip the switch open rapidly without the usual long delayprovided by devices of this character. It will be apparent that uponsudden heating of the heating element, the copper section of theexpansible element 72 will become heated and will expand while the ironsection will be kept cool by its proximity to the metal enclosing tube70 so that quick ex pansion of the device will result. On lower or moregradually applied overloads, the two metals of the spiral thermostaticelement will heat more or less uniformly, however.

While I have shown my device associated with an electric switch forpurposes of illustration. the device can be used for other purposes withlittle or no modification as will be apparent.

I claim:

1. In a thermo-responsive apparatus, the combination of a movableholding member, a. plurality of thermo-responsive devices having meanswhereby they can be initially set to operate in accordance with any oneof a plurality of predetermined conditions, means connecting saiddevices with said holding member by which all thermo-responsive devicesconjointly and also each thermo-responsive device independently of theothers can actuate said llfilfllllfl' member. and means forsimultaneously varying the settings of said thermo-responsive devices.

2. In a thermo-rcsponsivc apparatus. the combination of a plurality of.thermomespom sire members having independent and fixed supports onwhich they are separately adjustable. actuating means controlled by saidmembers singly and also in unison. and means to effect the simultaneousadjustment of all said members on their several Fll]')]')lf)I'tS in thesome [lira-lion.

fl. In a thcrmo-rcsponsive apparatus. the ciunliinzllimi of a pluralityof separately- :ufing adjustable thermo-responsive members which are res'mnsivc to diii crent conditions having individual adjustment elements,means separately and also conjointly controlled by said members, andmeans to effect the simultaneous adjustment of said I118lll hersrelatively to said controlled means ineluding an adjustment-memberhaving connections with said adjusting elements of all saidthermo-responsive members by which said thermo-responsive members canact separately and also conjointly on said controlled means.

4. In a thermo-responsive device, the combination of a thermallyexpansible member having a free end, a fixed end, a rotatable supportfor the fixed end and a fixedly supported heating element for saidexpansible member extended lengthwise thereof and located within saidrotatable support.

5. In a thermo-responsive device, a thermally expansible element ofhelical formation having a fixed end and. a tree end, means to vary thesetting of said expansible element including means to rotate saidelement, and a fixedly supported heating element extended through saidrotatable expansible elei uent.

6. In a thermo-responsive device, a thermally expansible element ofhelical formation having a fixed end and a free end, a rotatable supportfor the fixed end generally coaxially disposed with the axis of saidhelical element, and a heating element having fixed supporting meanstherefor extended through said helical element.

7. In a thermo-responsive device. a thermally expansible element, anenclosing tube surrounding said element, said element having one endfixed to said tube and a free end extended outwardly through a wall ofsaid tube intermediate its ends, said tube characterized by beingrotatable about its axis, means to hold said tube in any rotatedposition thereof. and an electric heating element extended through saidtube and said expansible element.

8. In a therIno-responsive device. a. thermally expansible element ofhelical formation. an enclosing tube surrounding said element. saidelement having one end fixedto said tube and a free end extendedoutwardly of said tube, said tube characterized by being rotatable aboutits axis, means to rotate said tube. means to hold said tube in anyrotated position thereof. and an ele tric heating element extendedtl'irough said tube and said expansible element.

9. In a thermo-responsive device, a tube of substantial length. supportsfor the ends of said tube on which said tube is rotatable. a thermallyexpansible element of generall helical formation disposed within saidtide and having one end thereof fixed thereto and having the other endt'reely extended outwardly of said tube, and a heating member to beatsaid expansible helical element located therein.

10. In a thorniii-responsive device. a supporting bracket having a pairof spaced coaxial shoulders, a cylindrical tube having its open endsencircling and journalled upon said shoulders, and a thermallyexpansible element of helical formation received within said tube havingone end fixed to said tube intermediate its ends, and means to hold saidtube against rotation on its journals in any one of a plurality ofangularly related positions and having its other end freely extendedoutwardly of said tube.

11. In t1tllQIlllO-lCSpOIlE-IVE device, the combination of a rotatablysupported tube, an electric heating element located within said tube, athermally expansible element disposed alongside said heating elementwithin and rotatable with and having one end fixed to said tube andhaving a radially-extended free end, means operated by said free end,and means to fix said tube against rotation on its support in any one ofa plurality of positions.

12. In a thermo-responsive device. the combination of a supportingbracket, a sore w having an enlarged cylindrical head carried by saidbracket at one end, an insulating bushing carried by said bracket at theother end. a tube loosely received on said bushing and the head of saidscrew and rotatable on both, a thermally expansible element. receivedwithin said tube and having one end fixed to said tube and having itsother end extended freely outwardly of said tube, and a heating elementextended within said tube adjacent said expansible element having oneend thereof conneeted electrically with said screw and having anelectrical connection at its other end extended through said bushing.

13. In a thermo-responsive device the combination of a cylindricalheat-absorbing metal tube, a generally cylindrical thermally expansiblemember composed of two sections having different coefficients ofexpansion received within said tube and having its most expansiblesection innermost and its least expansible section closely adjacent andin heattransferring relation with said metal tube and a heater elementdisposed within said tube adjacent said most expansible section.

14. In a thermo-responsive device, the combination of a U-shapedsupporting frame having spaced upstanding side walls. a pivotallysupported tripping frame disposed adjacent one of said side walls, aspring urging said frame for rotation about its pivot, a holding framedisposed beneath said tripping frame and normally engageable therewithto hold it from engagement, and a thcrmoresponsivc device carried by theother wall of said supporting frame at one side of said holding framehaving an operative connection with said holding frame and arranged tomove it to release said tripping frame.

15. In a thermo-responsive device, a bracket having spaced parallelarms,

aligned confronting cylindrical supports carried by said arms, one ofwhich supports is connected electrical with and the other is insulatedfrom sai bracket, a tube extended between said arms and rotatable onsaid supports, a helical thermo-expansible member located within saidtube and having one end fixed thereto and the other end extended freelylaterally through an opening in the side wall of said tube, and aheating member extended through said helical member having one endconnected to said electrically-connected sup ort and its other endextended through sai insulated sup ort.

16. A thermo-res onsive device aving the combination 0 a tripping frame,a spring urging said frame for movement into an operated position, aholding frame normally holding said tripping rame in an inoperatedposition against the action of said spring, a plurality ofthermally-expansive members each having a fixed end and a movable freeend, said free ends having independent lost-motion connections with saidholding frame by which each thermally-expansive member independently canoperate said holding frame, and adjusting means connected with all ofthe fixed ends of said thermally-expansible members are arranged to movesaid ends in unison.

17. A thermo-responsive device having the combination of a supportingframe having an upstanding wall, a tripping frame having a pivotalsuport on said supportin frame and located on one side of said wal aspring urging said tripping frame for movement to an operated position,a holding frame having a pivotal support on said supporting frame andlocated on the same side of said well with said tripping frame andarranged to hold said tripping frame normally in an unoperated position,thermoresponsive means to depress said holding frame and to move it outof holding relation with said tripping frame, and a resetting memberlocated mainly on the side of said wall opposite said tripping framehaving an extension which is extended through an opening in said walland is normally free from said tripping frame and is movable intoengagement therewith in a direction to return it to the engagement ofsaid holding frame.

18. A thermo-responsive device having the combination of a U-shapedsupporting frame, a tripping frame comprising a pair of spaced plateshaving a pivotal connection with said supportin frame, a rollerjournalled between said p ates, a spring engaging said tripping frameurging it toward an operated position, a holding frame comprising a pairof spaced L-shaped members having a pivotal connection at one end withsaid supporting frame and having a roller located between the other endsthere- Patent No. 1,872,208.

CERTIFICATE OF CORRECTION.

August 16, 1932.

JOSEPH D. WOOD.

it is hereby certified that error appears in-the printed specificationof the above numbered patent requiring correction as follows: Page 3,line 71, claim 10, beginning with the word "intermediate" strike out allto and including the word "positions" in line 74, and line 75, sameclaim, after the word "tube" insert the words intermediate its ends, andmeans to hold said tube against rotation on its journals in any one of aplurality of angularly related positions; and that the said LettersPatent should be read with this correction therein that the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 22nd day of November, A. l) i932.

M. J. Moore,

(Seal) Acting Commissioner of Patents.

